Context Navigation

Introduction

It is useful for a variety of reasons to determine if a connection is coming from a Tor node. Early attempts to determine if a given IP address was a Tor exit used the directory to match IP addresses and exit policies. This approach had a number of drawbacks, including false negatives when a Tor router exits traffic from a different IP address than its OR port listens on. The ​Tor DNS-based Exit List was designed to overcome these problems and provide a simple interface for answering the question: is this a Tor exit?

Implementation

An implementation of the Tor DNS Exit List has been completed at ​exitlist.torproject.org. DNS queries are answered via this host in the manner described in the design document. The exit nodes are tested regularly to avoid the false negatives when inspecting the directory entries alone.

Examples

The following examples describe how to utilize this service in various ways. Please add to this list if you have implemented hooks for a language or framework not provided below.